CCND1 and brain neoplasm: Previous experimental studies found that the rs603965 polymorphism was located at the conjunction of exon 4 and intron 4 of CCND1 gene, the G to A variation in this locus was associated with a shorter transcription and a 55 amino acids loss of the C‐terminal domain of CCND1 (Jeon, Kim, Jeong, Bae, & Jung, 2018; Vodicka et al., 2018), which may greatly alter the activity of CCND1 and give rise to the development of brain tumor.